Feat: adding some basic music theory

crates/forth/src/ops.rs

@@ -53,6 +53,8 @@ pub enum Op {
     Set,
     GetContext(String),
     Rand,
+    ExpRand,
+    LogRand,
     Seed,
     Cycle,
     PCycle,
@@ -86,6 +88,7 @@ pub enum Op {
     Generate,
     GeomRange,
     Times,
+    Chord(&'static [i64]),
     // MIDI
     MidiEmit,
     GetMidiCC,

crates/forth/src/theory/chords.rs

@@ -0,0 +1,129 @@
+pub struct Chord {
+    pub name: &'static str,
+    pub intervals: &'static [i64],
+}
+
+pub static CHORDS: &[Chord] = &[
+    // Triads
+    Chord {
+        name: "maj",
+        intervals: &[0, 4, 7],
+    },
+    Chord {
+        name: "m",
+        intervals: &[0, 3, 7],
+    },
+    Chord {
+        name: "dim",
+        intervals: &[0, 3, 6],
+    },
+    Chord {
+        name: "aug",
+        intervals: &[0, 4, 8],
+    },
+    Chord {
+        name: "sus2",
+        intervals: &[0, 2, 7],
+    },
+    Chord {
+        name: "sus4",
+        intervals: &[0, 5, 7],
+    },
+    // Seventh chords
+    Chord {
+        name: "maj7",
+        intervals: &[0, 4, 7, 11],
+    },
+    Chord {
+        name: "min7",
+        intervals: &[0, 3, 7, 10],
+    },
+    Chord {
+        name: "dom7",
+        intervals: &[0, 4, 7, 10],
+    },
+    Chord {
+        name: "dim7",
+        intervals: &[0, 3, 6, 9],
+    },
+    Chord {
+        name: "m7b5",
+        intervals: &[0, 3, 6, 10],
+    },
+    Chord {
+        name: "minmaj7",
+        intervals: &[0, 3, 7, 11],
+    },
+    Chord {
+        name: "aug7",
+        intervals: &[0, 4, 8, 10],
+    },
+    // Sixth chords
+    Chord {
+        name: "maj6",
+        intervals: &[0, 4, 7, 9],
+    },
+    Chord {
+        name: "min6",
+        intervals: &[0, 3, 7, 9],
+    },
+    // Extended chords
+    Chord {
+        name: "dom9",
+        intervals: &[0, 4, 7, 10, 14],
+    },
+    Chord {
+        name: "maj9",
+        intervals: &[0, 4, 7, 11, 14],
+    },
+    Chord {
+        name: "min9",
+        intervals: &[0, 3, 7, 10, 14],
+    },
+    Chord {
+        name: "dom11",
+        intervals: &[0, 4, 7, 10, 14, 17],
+    },
+    Chord {
+        name: "min11",
+        intervals: &[0, 3, 7, 10, 14, 17],
+    },
+    Chord {
+        name: "dom13",
+        intervals: &[0, 4, 7, 10, 14, 21],
+    },
+    // Add chords
+    Chord {
+        name: "add9",
+        intervals: &[0, 4, 7, 14],
+    },
+    Chord {
+        name: "add11",
+        intervals: &[0, 4, 7, 17],
+    },
+    Chord {
+        name: "madd9",
+        intervals: &[0, 3, 7, 14],
+    },
+    // Altered dominants
+    Chord {
+        name: "dom7b9",
+        intervals: &[0, 4, 7, 10, 13],
+    },
+    Chord {
+        name: "dom7s9",
+        intervals: &[0, 4, 7, 10, 15],
+    },
+    Chord {
+        name: "dom7b5",
+        intervals: &[0, 4, 6, 10],
+    },
+    Chord {
+        name: "dom7s5",
+        intervals: &[0, 4, 8, 10],
+    },
+];
+
+pub fn lookup(name: &str) -> Option<&'static [i64]> {
+    CHORDS.iter().find(|c| c.name == name).map(|c| c.intervals)
+}

crates/forth/src/theory/mod.rs

@@ -1,3 +1,4 @@
+pub mod chords;
 mod scales;
 
 pub use scales::lookup;

crates/forth/src/vm.rs

@@ -455,11 +455,37 @@ impl Forth {
                             let a_f = a.as_float()?;
                             let b_f = b.as_float()?;
                             let (lo, hi) = if a_f <= b_f { (a_f, b_f) } else { (b_f, a_f) };
-                            let val = self.rng.lock().unwrap().gen_range(lo..hi);
+                            let val = if (hi - lo).abs() < f64::EPSILON {
+                                lo
+                            } else {
+                                self.rng.lock().unwrap().gen_range(lo..hi)
+                            };
                             stack.push(Value::Float(val, None));
                         }
                     }
                 }
+                Op::ExpRand => {
+                    let hi = stack.pop().ok_or("stack underflow")?.as_float()?;
+                    let lo = stack.pop().ok_or("stack underflow")?.as_float()?;
+                    if lo <= 0.0 || hi <= 0.0 {
+                        return Err("exprand requires positive values".into());
+                    }
+                    let (lo, hi) = if lo <= hi { (lo, hi) } else { (hi, lo) };
+                    let u: f64 = self.rng.lock().unwrap().gen();
+                    let val = lo * (hi / lo).powf(u);
+                    stack.push(Value::Float(val, None));
+                }
+                Op::LogRand => {
+                    let hi = stack.pop().ok_or("stack underflow")?.as_float()?;
+                    let lo = stack.pop().ok_or("stack underflow")?.as_float()?;
+                    if lo <= 0.0 || hi <= 0.0 {
+                        return Err("logrand requires positive values".into());
+                    }
+                    let (lo, hi) = if lo <= hi { (lo, hi) } else { (hi, lo) };
+                    let u: f64 = self.rng.lock().unwrap().gen();
+                    let val = hi * (lo / hi).powf(u);
+                    stack.push(Value::Float(val, None));
+                }
                 Op::Seed => {
                     let s = stack.pop().ok_or("stack underflow")?.as_int()?;
                     *self.rng.lock().unwrap() = StdRng::seed_from_u64(s as u64);
@@ -607,6 +633,13 @@ impl Forth {
                     stack.push(result);
                 }
 
+                Op::Chord(intervals) => {
+                    let root = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    for &interval in *intervals {
+                        stack.push(Value::Int(root + interval, None));
+                    }
+                }
+
                 Op::Oct => {
                     let shift = stack.pop().ok_or("stack underflow")?;
                     let note = stack.pop().ok_or("stack underflow")?;

crates/forth/src/words.rs

@@ -473,6 +473,26 @@ pub const WORDS: &[Word] = &[
         compile: Simple,
         varargs: false,
     },
+    Word {
+        name: "exprand",
+        aliases: &[],
+        category: "Probability",
+        stack: "(lo hi -- f)",
+        desc: "Exponential random biased toward lo. Both args must be positive",
+        example: "1.0 100.0 exprand => 3.7",
+        compile: Simple,
+        varargs: false,
+    },
+    Word {
+        name: "logrand",
+        aliases: &[],
+        category: "Probability",
+        stack: "(lo hi -- f)",
+        desc: "Exponential random biased toward hi. Both args must be positive",
+        example: "1.0 100.0 logrand => 87.2",
+        compile: Simple,
+        varargs: false,
+    },
     Word {
         name: "seed",
         aliases: &[],
@@ -810,6 +830,292 @@ pub const WORDS: &[Word] = &[
         compile: Simple,
         varargs: false,
     },
+    // Chords - Triads
+    Word {
+        name: "maj",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth)",
+        desc: "Major triad",
+        example: "c4 maj => 60 64 67",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "m",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth)",
+        desc: "Minor triad",
+        example: "c4 m => 60 63 67",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dim",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth)",
+        desc: "Diminished triad",
+        example: "c4 dim => 60 63 66",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "aug",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth)",
+        desc: "Augmented triad",
+        example: "c4 aug => 60 64 68",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "sus2",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root second fifth)",
+        desc: "Suspended 2nd",
+        example: "c4 sus2 => 60 62 67",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "sus4",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root fourth fifth)",
+        desc: "Suspended 4th",
+        example: "c4 sus4 => 60 65 67",
+        compile: Simple,
+        varargs: true,
+    },
+    // Chords - Seventh
+    Word {
+        name: "maj7",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Major 7th",
+        example: "c4 maj7 => 60 64 67 71",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "min7",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Minor 7th",
+        example: "c4 min7 => 60 63 67 70",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dom7",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Dominant 7th",
+        example: "c4 dom7 => 60 64 67 70",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dim7",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Diminished 7th",
+        example: "c4 dim7 => 60 63 66 69",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "m7b5",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Half-diminished (min7b5)",
+        example: "c4 m7b5 => 60 63 66 70",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "minmaj7",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Minor-major 7th",
+        example: "c4 minmaj7 => 60 63 67 71",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "aug7",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh)",
+        desc: "Augmented 7th",
+        example: "c4 aug7 => 60 64 68 70",
+        compile: Simple,
+        varargs: true,
+    },
+    // Chords - Sixth
+    Word {
+        name: "maj6",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth sixth)",
+        desc: "Major 6th",
+        example: "c4 maj6 => 60 64 67 69",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "min6",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth sixth)",
+        desc: "Minor 6th",
+        example: "c4 min6 => 60 63 67 69",
+        compile: Simple,
+        varargs: true,
+    },
+    // Chords - Extended
+    Word {
+        name: "dom9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh ninth)",
+        desc: "Dominant 9th",
+        example: "c4 dom9 => 60 64 67 70 74",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "maj9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh ninth)",
+        desc: "Major 9th",
+        example: "c4 maj9 => 60 64 67 71 74",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "min9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh ninth)",
+        desc: "Minor 9th",
+        example: "c4 min9 => 60 63 67 70 74",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dom11",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh ninth eleventh)",
+        desc: "Dominant 11th",
+        example: "c4 dom11 => 60 64 67 70 74 77",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "min11",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh ninth eleventh)",
+        desc: "Minor 11th",
+        example: "c4 min11 => 60 63 67 70 74 77",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dom13",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh ninth thirteenth)",
+        desc: "Dominant 13th",
+        example: "c4 dom13 => 60 64 67 70 74 81",
+        compile: Simple,
+        varargs: true,
+    },
+    // Chords - Add
+    Word {
+        name: "add9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth ninth)",
+        desc: "Major add 9",
+        example: "c4 add9 => 60 64 67 74",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "add11",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth eleventh)",
+        desc: "Major add 11",
+        example: "c4 add11 => 60 64 67 77",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "madd9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth ninth)",
+        desc: "Minor add 9",
+        example: "c4 madd9 => 60 63 67 74",
+        compile: Simple,
+        varargs: true,
+    },
+    // Chords - Altered dominants
+    Word {
+        name: "dom7b9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh flatninth)",
+        desc: "7th flat 9",
+        example: "c4 dom7b9 => 60 64 67 70 73",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dom7s9",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third fifth seventh sharpninth)",
+        desc: "7th sharp 9 (Hendrix chord)",
+        example: "c4 dom7s9 => 60 64 67 70 75",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dom7b5",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third flatfifth seventh)",
+        desc: "7th flat 5",
+        example: "c4 dom7b5 => 60 64 66 70",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "dom7s5",
+        aliases: &[],
+        category: "Chord",
+        stack: "(root -- root third sharpfifth seventh)",
+        desc: "7th sharp 5",
+        example: "c4 dom7s5 => 60 64 68 70",
+        compile: Simple,
+        varargs: true,
+    },
     // LFO
     Word {
         name: "ramp",
@@ -2508,6 +2814,8 @@ pub(super) fn simple_op(name: &str) -> Option<Op> {
         "sound" => Op::NewCmd,
         "." => Op::Emit,
         "rand" => Op::Rand,
+        "exprand" => Op::ExpRand,
+        "logrand" => Op::LogRand,
         "seed" => Op::Seed,
         "cycle" => Op::Cycle,
         "pcycle" => Op::PCycle,
@@ -2654,6 +2962,11 @@ pub(super) fn compile_word(
         return true;
     }
 
+    if let Some(intervals) = theory::chords::lookup(name) {
+        ops.push(Op::Chord(intervals));
+        return true;
+    }
+
     if let Some(word) = lookup_word(name) {
         match &word.compile {
             Simple => {

tests/forth.rs

@@ -54,3 +54,6 @@ mod generator;
 
 #[path = "forth/midi.rs"]
 mod midi;
+
+#[path = "forth/chords.rs"]
+mod chords;

tests/forth/chords.rs

@@ -0,0 +1,178 @@
+use cagire::forth::Value;
+
+use super::harness::{expect_stack, run};
+
+fn ints(vals: &[i64]) -> Vec<Value> {
+    vals.iter().map(|&v| Value::Int(v, None)).collect()
+}
+
+// Triads
+
+#[test]
+fn chord_major() {
+    expect_stack("c4 maj", &ints(&[60, 64, 67]));
+}
+
+#[test]
+fn chord_minor() {
+    expect_stack("c4 m", &ints(&[60, 63, 67]));
+}
+
+#[test]
+fn chord_diminished() {
+    expect_stack("c4 dim", &ints(&[60, 63, 66]));
+}
+
+#[test]
+fn chord_augmented() {
+    expect_stack("c4 aug", &ints(&[60, 64, 68]));
+}
+
+#[test]
+fn chord_sus2() {
+    expect_stack("c4 sus2", &ints(&[60, 62, 67]));
+}
+
+#[test]
+fn chord_sus4() {
+    expect_stack("c4 sus4", &ints(&[60, 65, 67]));
+}
+
+// Seventh chords
+
+#[test]
+fn chord_maj7() {
+    expect_stack("c4 maj7", &ints(&[60, 64, 67, 71]));
+}
+
+#[test]
+fn chord_min7() {
+    expect_stack("c4 min7", &ints(&[60, 63, 67, 70]));
+}
+
+#[test]
+fn chord_dom7() {
+    expect_stack("c4 dom7", &ints(&[60, 64, 67, 70]));
+}
+
+#[test]
+fn chord_dim7() {
+    expect_stack("c4 dim7", &ints(&[60, 63, 66, 69]));
+}
+
+#[test]
+fn chord_half_dim() {
+    expect_stack("c4 m7b5", &ints(&[60, 63, 66, 70]));
+}
+
+#[test]
+fn chord_minmaj7() {
+    expect_stack("c4 minmaj7", &ints(&[60, 63, 67, 71]));
+}
+
+#[test]
+fn chord_aug7() {
+    expect_stack("c4 aug7", &ints(&[60, 64, 68, 70]));
+}
+
+// Sixth chords
+
+#[test]
+fn chord_maj6() {
+    expect_stack("c4 maj6", &ints(&[60, 64, 67, 69]));
+}
+
+#[test]
+fn chord_min6() {
+    expect_stack("c4 min6", &ints(&[60, 63, 67, 69]));
+}
+
+// Extended chords
+
+#[test]
+fn chord_dom9() {
+    expect_stack("c4 dom9", &ints(&[60, 64, 67, 70, 74]));
+}
+
+#[test]
+fn chord_maj9() {
+    expect_stack("c4 maj9", &ints(&[60, 64, 67, 71, 74]));
+}
+
+#[test]
+fn chord_min9() {
+    expect_stack("c4 min9", &ints(&[60, 63, 67, 70, 74]));
+}
+
+#[test]
+fn chord_dom11() {
+    expect_stack("c4 dom11", &ints(&[60, 64, 67, 70, 74, 77]));
+}
+
+#[test]
+fn chord_min11() {
+    expect_stack("c4 min11", &ints(&[60, 63, 67, 70, 74, 77]));
+}
+
+#[test]
+fn chord_dom13() {
+    expect_stack("c4 dom13", &ints(&[60, 64, 67, 70, 74, 81]));
+}
+
+// Add chords
+
+#[test]
+fn chord_add9() {
+    expect_stack("c4 add9", &ints(&[60, 64, 67, 74]));
+}
+
+#[test]
+fn chord_add11() {
+    expect_stack("c4 add11", &ints(&[60, 64, 67, 77]));
+}
+
+#[test]
+fn chord_madd9() {
+    expect_stack("c4 madd9", &ints(&[60, 63, 67, 74]));
+}
+
+// Altered dominants
+
+#[test]
+fn chord_dom7b9() {
+    expect_stack("c4 dom7b9", &ints(&[60, 64, 67, 70, 73]));
+}
+
+#[test]
+fn chord_dom7s9() {
+    expect_stack("c4 dom7s9", &ints(&[60, 64, 67, 70, 75]));
+}
+
+#[test]
+fn chord_dom7b5() {
+    expect_stack("c4 dom7b5", &ints(&[60, 64, 66, 70]));
+}
+
+#[test]
+fn chord_dom7s5() {
+    expect_stack("c4 dom7s5", &ints(&[60, 64, 68, 70]));
+}
+
+// Different roots
+
+#[test]
+fn chord_a3_min7() {
+    expect_stack("a3 min7", &ints(&[57, 60, 64, 67]));
+}
+
+#[test]
+fn chord_e4_dom7s9() {
+    expect_stack("e4 dom7s9", &ints(&[64, 68, 71, 74, 79]));
+}
+
+#[test]
+fn chord_with_integer_root() {
+    let f = run("60 maj");
+    let stack = f.stack();
+    assert_eq!(stack, ints(&[60, 64, 67]));
+}

tests/forth/randomness.rs

@@ -105,3 +105,74 @@ fn ftom_880() {
 fn mtof_ftom_roundtrip() {
     expect_float("60 mtof ftom", 60.0);
 }
+
+#[test]
+fn exprand_in_range() {
+    let f = forth_seeded(12345);
+    f.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    let val = stack_float(&f);
+    assert!(val >= 1.0 && val <= 100.0, "exprand {} not in [1, 100]", val);
+}
+
+#[test]
+fn exprand_deterministic() {
+    let f1 = forth_seeded(99);
+    let f2 = forth_seeded(99);
+    f1.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    f2.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn exprand_swapped_args() {
+    let f1 = forth_seeded(42);
+    let f2 = forth_seeded(42);
+    f1.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    f2.evaluate("100.0 1.0 exprand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn exprand_requires_positive() {
+    expect_error("0.0 10.0 exprand", "exprand requires positive values");
+    expect_error("-1.0 10.0 exprand", "exprand requires positive values");
+    expect_error("1.0 0.0 exprand", "exprand requires positive values");
+}
+
+#[test]
+fn logrand_in_range() {
+    let f = forth_seeded(12345);
+    f.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    let val = stack_float(&f);
+    assert!(val >= 1.0 && val <= 100.0, "logrand {} not in [1, 100]", val);
+}
+
+#[test]
+fn logrand_deterministic() {
+    let f1 = forth_seeded(99);
+    let f2 = forth_seeded(99);
+    f1.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    f2.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn logrand_swapped_args() {
+    let f1 = forth_seeded(42);
+    let f2 = forth_seeded(42);
+    f1.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    f2.evaluate("100.0 1.0 logrand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn logrand_requires_positive() {
+    expect_error("0.0 10.0 logrand", "logrand requires positive values");
+    expect_error("-1.0 10.0 logrand", "logrand requires positive values");
+    expect_error("1.0 0.0 logrand", "logrand requires positive values");
+}
+
+#[test]
+fn rand_equal_bounds() {
+    expect_float("5.0 5.0 rand", 5.0);
+}